Transmitter for wireless telephony.



W T DITGHAM TRANSMITTER FOB WIRELESS TELEPHONY.

APPLIOATIOR TILED AP EJ), 1913.

Patented Mar. 3,1914.

A 9 A 1 E M 1 kw 0H UH 0H hm? AW kw? a x a w my W W W W E B R L. fim 3 w L y //v YEA/70,

ozww MW.

W TNESSES.

WILLIAM THEODORE DITCHAM, F T'WICKENHAM, ENGLAND.

TRANSMITTER FOR WIRELESS TELEPHONY.

Specification of Letters mtenr.

Application filed April 9, 1913.

Patented Mair, it, itiii,

Serial No. 759,397.

To 0'52 coiimh it may concern."

Be it known that 1, WILLIAM Tnnononn rrorm'ir, subject of the King of Grout thin. residing; st 4 Lebanon Park Moniiu'ichc bum, in the county of Midflilnglond, have invented new and useiui inu rovements in Transmitters for ii irelcss Teiephony, of which the following is o specification.

For Wireless telephony this invention rcutcs to improved means for producing elec- "iifl 'illii fjjiiktlc woven-nine of n group-ire i'ucy exceeding the limits of oudibility ,mposing thereon a 'voicechorcc- :irot To generate the required rapid :mcrcssion oi sparks by the energy of direct mix-rent electricity, Ii moire use of the known orrsiugement of leading the electric energy to and from :i spurlogep through inductive resir'tnnres, o shunt-circuit containing it conion end on inductance being provided herewith. To prevent the failure of the op :rntion hr the production of a continuous rc in sui. ,itution for a. succession of sparks, i tal ie udvantsge of the known devices of growth promoting the cooling or the clectrodes by forming them of relatively large muss udupted to conduct heat rapidly away from their spin-king extremities, mounting them so that they may be rotated with fecilil'y and thereby present successive sparle inc; points, employing an air blast, surrounding them with an otmosphere'consistin of or comprising hydrogen, or immersing t em in on insulating: liquid. ()n-these means for preyenting arcing is superposed a tightcoupling between the inductance of the energized shunt-circuit and the inductance of the rru i'iet' hes, in wireless telcgrephy, previously been proposed, in conjunction with good radiating properties oi the antenna, to absorb compictcly the energy of the primary circuit and radiate it into the surrounding medium. Such transfer of energy from the spark-gap w'il stiil further augment the ossible fro rmency oi? sporking Without arcing. In addition preferebiy advantage is taken of the known device ct employing two short rods dissimilar metals for the electrodes of the spark gap such as, for example, copper and silver or copper and aluminum, tne throes of the rods being parallel and closely adjacent and connected to masses of heatconduoting metal. In order to perform the 1g air-wire, which tight-coupling double "function of tight-coupling the in ductoncc of [he energized shunt-circuit with the iiulurtnncc of the rudiutiug nir-wirc cud sul'ierposing on the soundlcss electro-1nugnctic wares, which are transmitted from the radiating air-wire, :1 voice charectcrimtion there intinposcd u circuit which is c0nductirely continuous through a microphone or cquivulcnt thereof thut is, a circuit which does not contain :1 corulcnser and therefore does not possess u definite frequency of uracil lotion the said interposed microphone circuit having on inductumo which is tightiycoupled to the induciunre of the energized shunt-circuit and another inductance which is lightly muplml to that of the radiating: uir-wire. The iudu tuurcs shove mentioned are pm i'er:1bly so iill'klllg'iii that the inducicnr-c oi the sluint-circuit cannot directly of feet the inductance of the rzulirding uirwire to any opprcciuhlo degree. the latter being; influenced by the former only through the mcdiiuu, of the interposed n'iicrophone circuit. In. effecting the said tiglit couplingg through the medium of the said interposed microphone circi'lit, one oi the inductonces oi the letter may serve also for the inductance of the shunt-circuit or for the inductance of the radiating sirwrire.

In place of un elevated air-Wire the wave trains may be rruiizdcd from a, long horizontol insuiutcd wire hiid on or below the ground or suspended at short distance above the ground, and inductively or galvnuicuily connected at its center part to the condenser shunt-circuit, and the said horizontal wire may have its ends left free or its ends may be connected to the earth through condensers,

On the accompanying drawing are shown diogremniaticully, three .difi'erent arrangements of the above mentioned clmncnts in the described interposed microphone circuit. In each of the three figures the circuit which is energized by the direct-current supply is the some and is similarly lettered, L If being the direct-current supply leans, I I choking coils contained therein. R is a. resistence. S is the spark-gap, indicated as a cooled spark-gap, and C is a condenser and I an inductance contained in the shunt-oi cuit. The radiating eirwire is indicated by A, I being the inductance contained therein and E the earth or countencepecity.

In Figure 1 the interposed microphone circuit comprises an inductance I tightlycoupled with the inductance I of the shuntcircuit and another inductance I tightlycoupled with the inductance I of the radiating air-wire, the inductance I being so situated relatively to the inductance I as for example by placing the axes of the coils at right-angles to one another, that the inductance I cannot directly afl'ect the inductance I. In Fig. 2 the arrangement is varied by causing theinductance I in the radiating air-wire to serve also the purpose of the before-mentioned inductance I in Fig. 1. By such a modified construction the inductance ofthe interposed circuit will be virtually coupled to the inductance of the radiating air-wire with the maximum degree of tightness as far as the dimensions of the inductance I will allow. Similarly in Fig. 3 the before-mentioned inductance I is made to serve, in addition, the function of the beforemcntioned inductance I" so that these inductances may be regarded as being coupled with the maximum degree of tightness.

and a condenser and an inductance in paral- 101 with said spark gap, a radiating air Wire, an inductance in said air wire inductively separated from said spark circuit inductance, a continuous circuit tightly coupled to said spark circuit inductance and to said air wire inductanceland a microphone in said continuous circuit.

In testimony whereof I have signed my name to this specification in the" presence of two subscriblng witnesses.

WILLIAM THEODORE DITGHAM.

Witnesses:

ROBERT ARTHUR SMITH, GEORGE CASTLE. 

